Method of and a composition for treating tobacco or tobacco article treated by such method or composition



3,010,851 METH IED (W A COMPSSHTION FER AT- [NG TOBACCO R TOBACCQ ARTECLE TREAT- El) BY SUCH METHUD 0R CGMPGSI'HON Paul Vol-heck Molde, 18 Tonysvej, Copenhagen- Charlottenlund, Denmark No Drawing. Filed May 29, 1957, Ser. No. 662,348 Claims priority, application Germany June 1, 1956 6 Claims. (Cl. 131-17) The present invention relates to a method of treating tobacco and has for its purpose an improvement of the incineration and the ash-formation. An object of the invention is to obtain an ash which is more white and consistent than it is normally obtained by the known treatments of tobacco. A further object of the invention is to obtain such improvements without unfavorably affecting the taste of the tobacco smoke. In many cases an improvement of the taste may, in fact, be obtained.

The present invention is based on a series of realizations which all together or separately will assist in obtaining a much better result than it has hitherto been possible.

It has been found that certain aluminium salts when added to the tobacco will give a whiter ash and that the effect will be considerably greater than that obtainable by use of the same amounts of hitherto used calcium or magnesium salts. Thus it has been found that a considerable improvement of the ash-formation is obtained by a method which in accordance with the present invention includes the process of adding to the tobacco a solution of a material containing aluminium salt which is soluble in water, and which decomposes at the temperature at which the tobacco burns, said material being of such a kind that when dissolved in water at the concentration used it. has a hydrogen ion concentration corresponding to a pH-value of not less than 4, the tobacco being im pregnated with said material in an amount sufficient for obtaining an improvement in the whiteness and consistence of the ash produced by burning the tobacco.

It has further been found that by adding potassium salts together with aluminium salts, a whiter ash as well as an improved incineration may be obtained. Finally it has been found that by a combined addition of one or more aluminium salts and one or more calcium, magnesium, or zinc salts a further improvement of the white ness of the ash may be obtained without increasing the total amount of salts added to the tobacco, especially when the various metal salts are salts of the same acid or acids as the aluminum salts used. By further adding one or more potassium salts to a combination of salts as mentioned above the incineration of the tobacco may simultaneously be improved.

The effect of said ash improving metal salts on the taste of the tobacco smoke may be very difierent. In many cases aluminium salts will have the best effect, but in this respect it is also true that by a combined addition of salts of various metals results may be obtained which in many cases will mean a direct improvement of the taste of the smoke of the natural tobacco that cannot be obtained by means of salts of a single metal only.

Correspondingly it has been found that besides potassium salts also salts of the other alkali metals, for instance sodium and lithium, will improve the incineration of the tobacco and simultaneously change the taste of the tobacco smoke in various manners so that said salts may often with advantage wholly or partly substitute potassium salts in mixtures intended for improving the incineration of the tobacco as well as the qualities of the ash.

The special effect of the aluminium salts on the tobacco ash and the taste of the tobacco smoke is, no doubt, due to the great aflinity of aluminium to oxygen resulting 3,616,851 Patented Nov. 28, 1961 in a complete incineration of the tobacco, and it has also been found that such aluminium salts only which are decomposed at the incineration temperature of the tobacco have the said effect to a sufiiciently high degree and that aluminium oxide and aluminium hydroxide are in themselves without the said effect.

Aluminium salts of organic acids are often very much hydrolyzed in aqueous solutions so that a substantial portion of the aluminium is converted into ordinarily colloidally dissolved aluminium hydroxide which as stated is ineffective. It has now been found that the effect of such aluminium salts may be substantially enhanced when other salts are added simultaneously, such as for instance the said salts of alkli metal, calcium, magnesium or zinc when said salts are salts of the same acid or acids as the aluminium salts. Thereby the said hydrolysis of the aluminium salts is restrained so as to form more undissociated aluminium salt and less aluminium hydroxide. It has been found that particularly good results will in many cases be obtained by means of salts or salt mixtures which wholly or partly consist of formates.

As to salts of inorganic acid the general rule has up until now been that nitrates may be used in most cases, whereas chlorides should be avoided as far as possible, because they have a detrimental effect on the incineration and the taste of the tobacco smoke. However, extensive experiments have proved that this is not absolutely correct and that small amounts of chlorides or other halides, for instance bromides, when used together with salts of other acids will have a very favorable effect on the taste of the tobacco smoke as well as on the qualities of the ash, for instance its consistency, without simultaneously unfavorably afiecting the incineration. Even when separately used certain halides, such as basic aluminium chlorides, have in special cases been found applicable.

Furthermore, it has been found to be important for a good result of the present treatment, especially with regard to the taste of the tobacco smoke, that the added salts do not change the natural hydrogen ion concentration of the tobacco too much, this meaning in practice among other things that they are not added to the tobacco in the form of too acidly reacting solutions. Normal aluminium salts, such as the nitrate, the chloride and the formate, may for this reason be used in relatively small dosages rather exactly adjusted for. each separate tobacco, but this renders the practical application rather ditficult. A more widespread application is obtained either by the use of more or less basic aluminium salts, or by combining normal or weakly basic aluminium salts with other salts having a suitable buffer capacity, for instance potassium, calcium or magnesium formate. It has been found by experiments that it is generally of 'great importance for a good result that the hydrogen ion concentration of the used salt solution should as mentioned above correspond to a pH-value of not less than 4.

All the above-described advantages and characteristics of the said method will manifest themselves not only when it is desired, as is often the case in the manufacture of cigars and cigarillos, to add to the tobacco only substances to improve the incineration and ash qualities combined with the most favorable improvement of the taste. Said advantages may also be obtained when for the sake of manufacture or for other reasons it is necessary to add to the tobacco also substances of quite a different type, for instance the below-mentioned humidifying means, or substances as for instance sugar, licorice, essential oils or the like having substantially for their purpose to impart a special taste to the tobacco and which are particularly used in the manufacture of cigarettes and smoking tobacco, or substances which like glycerol and finished tobacco against too intensive shrinkage, but

which also more or less afiect the taste of the tobacco smoke. I v p p The present invention relates to a method of treating tobacco including tobacco leaf,i.e., the harvested and Wholly or partly dried and probably fermented tobacco leaves, as well as partly manufactured tobacco articles, i.e;, ready-cut wrappers and binders, and finished tobacco products thereof. 7 V 7 V The method according to the invention may by way of example be executedso that in a, manner known per se an a'queous solution of a suitablealuminum salt, for instance basic aluminum nitrate, chloride, or formate, is added to the tobacco by immersion, spraying or passing between moistened rollers or the like, the concentration of said solution being so adapted that the tobacco will absorb /4 to 10% of the salt inquesti-on calculated on the weight of thetobacco.

The method according to the invention may further be executed by moistening the tobacco in a manner known per so with an aqueous solution of normal or basic aluminium nitrate, chloride, or formateand one or more alkali formates, the proportion of the aluminum" salt and the alkali metal salts varying according to the requirements of the individual tobacco, but being for instance 1:1 by

weight, the concentration of the solution being so adjusted.

that the tobacco will absorb from the total amount of salts /2 to of its ownweight. in a fourth example selected at random the tobacco is moistened with an aqueous solution of aluminum formate mixed with zinc formate, magnesium nitrate, potassium formate, and sodium chloride in proportions of for inwater at the concentration used it has a hydrogen ion concentration corresponding to a pH-value of not less than 4, whereby the tobacco is impregnated with said material in an amount suflicient for obtaining an improvement in the whiteness and consistence of the ash produced by burning the tobacco. 2. In a method of treating tobacco the process of adding to the tobacco a solution of a material containing aluminum formate, the material being of such a kind that when dissolved in water at the concentration used it has a hydrogen 'ion concentration corresponding to a pH- value ofhot less than 4, whereby the tobacco is impregnated with said material in an amount suificient for obtaining an improvement in the whiteness and consistence of the ash produced by burning the tobacco. 3. In a method of treating tobacco the process of adding to the tobacco a solution of a material containing aluminum salt which decomposes at the temperature at which the tobacco burns,; the material further containing another salt of the same acid, the material being soluble in water and being of such a kind that when dissolved in water at the concentration used it has a hydrogen ion concentration corresponding to a pH-value of not less than 4, whereby the tobacco is impregnated with said material in anyamount sufficient for obtaining an improvement in the whiteness and consistence of the ash produced by burning the tobacco. V

4. A tobacco article having been treated by adding to the tobacco a solution of a material containing aluminum salt which is soluble in water and which decomposes at the temperature at which the tobacco burns, said material stance 4:1:2:4:1 by weight, the tobacco absorbing a total amount of solid matters corresponding to A2 to 20% of its own weight.

As the best results to be obtained by the examples of the method according to the invention will generally be determined by the most uniform distribution of the said salts in the tobacco, it will oftenbe preferable to' add to the said solutions for instance A to 1 perthousan'd of a capillarily active humidification means comprising for iristance a polymethylen'e oxide or a quaternary ammonium base. 'In some cases, when the question is aboutobtaining a very quick soaking of the tobacco, for instance by mechanical treatment of the wrappers of finished cigars or ciga'rillos, an addition for instance of 10 to 30 or more of a low-molecular and volatile alcohol, for instance methyl or ethyl alcohol, to the aqueous salt solution will be adequate. V f i Moreover, the treatment may be executed either on whole tobacco leaves or on the cuter rubbedtobacco and performed either as an independent operation or simultaneously with the addition to the tobacco, more particularly as far as cigarettes or smoking tobacco is concerned, of other substances known per se, such as sugar,

licorice, glycerol, essential oils, or the like.

Finally, finished tobacco products may, according to the invention, be treated in'the above-described manners, by use of a solution of one or more of said salts, or, more particularly as far as cigars and cigarillos are concerned, by powdering the latter in a manner known per se with a dry or wet powder containing powdered tobacco which has in accordance with the invention been prepared with one or more of the said salts and other substances for instance in any of the above-mentioned proportions.

What is claimed is:

1. In a method of treating tobacco the process of adding to the tobacco a solution of a material containing aluminum salt which is soluble in water and'which decomposes at the temperature at which the tobacco burns,

being of such a kind that when dissolved in water at the concentration used it has a hydrogen ion concentration corresponding to a pH-value of not less than 4, the tobacco having been impregnated with said material in an amount suflicient for obtaining an improvement in the whiteness and consistence of the ash produced by burning the tobacco.

5. A tobacco article having been treated by adding to the tobacco a solution of'a material containing aluminum formate, the-material being of such a kind that when dis solved inwater at the concentration used it has a hydrogen ion coricentration corresponding to a pH-value of not less than .4, the tobacco having been impregnated with said material in an amount sufiicient for obtaining an improvement in the whiteness and consistence of theash produced by burning the tobacco.-

6. A tobacco article having been treated by adding to the tobacco a solution of a material containing aluminum salt which decomposes at the temperature at which the tobacco burns, the material further containing another salt'of the same acid, the material being soluble in Water and being 'of such a kind that when dissolved in water at the concentration used it has a hydrogen ion concentration corresponding to a pH-value of not less than 4, the tobacco having been impregnated with said material in an amount sufiicient for obtaining an improvement in the whiteness and consistenceof the ash produced by burning the tobacco.

References Cited in the file of this patent UNITED STATES PATENTS 

4. A TOBACCO ARTICLE HAVING BEEN TREATED BY ADDING TO THE TOBACCO A SOLUTION OF A MATERIAL CONTAINING ALUMINUM SALT WHICH IS SOLUBLE IN WATER AND WHICH DECOMPOSES AT THE TEMPERATURE AT WHICH THE TOBACCO BURNS, SAID MATERIAL BEING OF SUCH A KIND THAT WHEN DISSOLVED IN WATER AT THE CONCENTRATION USED IT HAS A HYDROGEN ION CONCENTRATION CORRESPONDING TO A PH-VALUE OF NOT LESS THAN 4, THE TOBACCO HAVING BEEN IMPREGNATED WITH SAID MATERIAL IN AN AMOUNT SUFFICIENT FOR ABTAINING AN IMPROVEMENT IN THE WHITENESS AND CONSISTENCE OF THE ASH PRODUCED BY BURNING THE TOBACCO. 